code: def test_channel_drop():
      from speechbrain.augment.time_domain import ChannelDrop
  
      signal = torch.rand(4, 256, 8)
      ch_drop = ChannelDrop(drop_rate=0.5)
      output = ch_drop(signal)
      assert signal.shape == output.shape
  
      signal = torch.rand(4, 256, 8)
      ch_drop = ChannelDrop(drop_rate=0.0)
      output = ch_drop(signal)
      assert torch.equal(signal, output)
  
      signal = torch.rand(4, 256, 8)
      ch_drop = ChannelDrop(drop_rate=1.0)
      output = ch_drop(signal)
      assert torch.sum(output) == 0
  
file_path: speechbrain/tests/unittests/test_augment.py
imports: import os
  import torch
  import torchaudio
  from speechbrain.dataio.dataio import write_audio
label_desc: Use image node_id 9 for calling a global function with example usage: test_channel_drop() without return types